It is common to treat a variety of medical conditions by introducing medical devices into or onto the body. For example, a medical device may be implanted completely or partially into the esophagus, trachea, colon, urinary tract, and vascular system among other areas of a mammalian body. However, medical devices may result in biofilm formation or encrustation while present in the body.
Biofilm formation is a concern with medical devices due to a strong correlation between biofilm formation and infection incidence. To combat this, devices have been impregnated or coated with antimicrobial materials, which provide a slow, steady release of antimicrobials. This is not optimal since slow, steady state elution of antimicrobials can be sub-lethal to pathogens and may contribute to increased antimicrobial resistance. Exposure to sub-lethal antimicrobial concentrations is well-known to potentiate the development of antimicrobial resistance in microbes.
Other devices are available that include coatings of polymeric materials having antimicrobials provided on the surface of medical devices. Some of these medical devices have coatings with multiple polymeric materials and additional time-release coatings to control the release of active agents. However, it would be useful to provide a single type of substrate that may be used with a variety of different devices or materials.
Therefore, creating a way to deliver large initial doses of active agents followed by smaller, steady doses of active agents is desirable. For example, providing multiple doses of an antimicrobial is thought to be more effective in preventing biofilm formation and reducing the likelihood of microbes developing microbial resistance. Additionally, there is a need for technology with such benefits that can be applied to a variety of different medical devices.